Home Postcode finder NSW Oallen Oallen postcode NSW Oallen is a locality in New South Wales covered by postcode 2622. Postcode 2622 State or territory New South Wales (NSW) Region Canberra Add a free Oallen business listing Be the first listing in Oallen Common questionsWhat is the postcode for Oallen?Oallen, NSW has the postcode 2622.What state is Oallen in?Oallen is in New South Wales (NSW).Does postcode 2622 cover more than one suburb?Yes. Postcode 2622 covers 50 localities, so the postcode alone does not identify Oallen. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.